After looking through all that Quicksort code, I was sent back to the Obfuscated C Code Contest. (Some of the highlights over the years.) Many of the entries go for obfuscation and complexity over all else, but some have a beautiful coordination of form and content.

Two favorites in that vein, both from Brian Westley. This one from 1988 approximates Pi. It approximates it better if you increase the size of the circular pattern.

#define _ F-->00 || F-OO--;
long F=00,OO=00;
main(){F_OO();printf("%1.3f\n", 4.*-F/OO/OO);}F_OO()

This one, from 1990, squeezes a lot out of certain reserved keywords while avoiding the preprocessor (almost) entirely.


	double time, me= !0XFACE,

	not; int rested,   get, out;

	main(ly, die) char ly, **die ;{

	    signed char lotte,
dear; (char)lotte--;

	for(get= !me;; not){

	1 -  out & out ;lie;{

	char lotte, my= dear,

	**let= !!me *!not+ ++die;

"The gloves are OFF this time, I detest you, snot\n\0sed GEEK!");

	do {not= *lie++ & 0xF00L* !me;

	#define love (char*)lie -

	love 1 *!(not= atoi(let

	[get -me?

(char)lotte: my- *love -

	'I'  -  *love -  'U' -

	'I'  -  (long)  - 4 - 'U' ])- !!

	(time  =out=  'a'));} while( my - dear

	&& 'I'-1l  -get-  'a'); break;}}

(char)*lie++, (char)*lie++; hell:0, (char)*lie;

	get *out* (short)ly   -0-'R'-  get- 'a'^rested;

	do {auto*eroticism,

	that; puts(*( out

	    - 'c'

-('P'-'S') +die+ -2 ));}while(!"you're at it");
for (*((char*)&lotte)^=

	(char)lotte; (love ly) [(char)++lotte+

	!!0xBABE];){ if ('I' -lie[ 2 +(char)lotte]){ 'I'-1l ***die; }

	else{ if ('I' * get *out* ('I'-1l **die[ 2 ])) *((char*)&lotte) -=

	'4' - ('I'-1l); not; for(get=!
get; !out; (char)*lie  &  0xD0- !not) return!!


	do{ not* putchar(lie [out

	*!not* !!me +(char)lotte]);

	not; for(;!'a';);}while(

	    love (char*)lie);{
register this; switch( (char)lie

	[(char)lotte] -1 *!out) {

	char*les, get= 0xFF, my; case' ':

	*((char*)&lotte) += 15; !not +(char)*lie*'s';

	this +1+ not; default: 0xF +(char*)lie;}}}

	get - !out;

	if (not--)

	goto hell;

	    exit( (char)lotte);}

What the code does is pretty apt as well.